Synergistic organotin stabilizer compositions and resins stabilized therewith

ABSTRACT

An improved stabilized composition comprises a synergistic combination of an organic thiolanhydride and a monohydrocarbyl tin compound of the formula

Unite States atet n91 Stapfer 1*Aug. 12, 1975 SYNERGISTIC ORGANOTIN STABILIZER COMPOSITIONS AND RESINS STABILIZED TIIEREWITII [75] Inventor: Christian H. Stapfer, Aachen,

Germany [73] Assignee: Cincinnati Milacron Chemicals,

Incorporated, Reading, Ohio Notice: The portion of the term of this patent subsequent to July 2, l99l, has been disclaimed.

[22] Filed: June 18, 1974 21 Appl. No.: 480,487

Related US. Application Data [63] Continuation-impart of Ser. No. 189,038, Oct. 13, 197 l Pat. No. 3,822,233, which is a continuation-in-part of Ser. No. 780,888, Dec. 3, 1968, Pat. No. 3,630,993.

[52] US. Cl...... 260/45.75 S; 260/457 S; 252/406;

260/4575 T 511 Im. c1. cosr 6/00 581 Field of Search 260/4575 s, 45.7 s;

[56] References Cited UNITED STATES PATENTS 3,822,233 7/l974 Stapfer 260/4575 Primary Examiner-V. P. l-Ioke Attorney, Agem, or FirmFisher, Christen & Sabol 57 ABSTRACT carbon atom and n is a number from O to 1.5 varying in increments of one-half.

Halide containing resins stabilized with these compositions exhibit improved resistance to the development of early color during processing.

10 Claims, No Drawings SYNERGISTIC ORGANOTIN STABILIZER COMPOSITIONS AND RESINS STABILIZED THEREWITH 2 chain radicals producing anhydrides such as l-thiol-2 ethylhexoic and unsaturated alkyl radicals such as those producing thiol crotonic anhydride. The aryl radicals suitable for practicing the present invention in- This application is a continuation-in-part f my 5 elude unsubstituted aryl producing anhydrides such as pending application Ser. No. 189,038 filed Oct. 13, thiolbenzoic anhydride or alkyl substituted aryl radicals 1971, now US. Pat. No. 3,822,233 continuation-inproducing thiolanhydrides such as 2-tert.butylthiolbenpart of my earlier copending application Ser. No. zoic anhydride. An example of suitable thiolanhydrides 780,888, filed Dec. 3, 1968, now US. Pat, No, which have different R and R groups is thiollauricben- 3,630,993. I() zoic anhydride.

This invention relates to organotin stabilizers and T monohydrocarbyl tin compounds suitable for arhalide containing resins stabilized therewith. More parresting the development of early color in halogen con ticularly, the invention relates to a synergistic combinataining resins stabilized with organic thiolanhydrides tion of organic thiolanhydrides with monohydrocarbylinclude stannoic oxides, stannoie sulfides, stannoic tin compounds which reduces the development of early g oup attached to the tin atom. The hydrocarbyl group color during processing when incorporated as a stabi- Preferably Contains One I0 12 Carbon atoms and may e lizer in halogen containing re in an alkyl, aryl, alkaryl or aralkyl radical except butyl thi During recent years the use of thiolanhydrides correostannoic acid or butyl tin sulfide. Examples of this sponding to the formula group of compounds include methylstannoic acid,

methylthiostannoic acid, butyl stannoic acid, butyl tin oxide, n-octyl stannoie acid, isooctyl stannoic acid, n-

octyl thiostannoic acid, isooctyl thiostannoic acid and CSCR- phenyl stannoic acid. These compounds frequently exist in the form of polymers which are condensation herein R and R are independently selected hydro- Products of the above stannoic and thiostannoic acids carbon groups with six to 20 carbon atoms, h b as well as mixtures of stannoic and thiostannoic acids.

contemplated as stabilizers against the thermal decorri- The Condensation Products y Contain 2 to 1,000

position of halogen containing resins, and particularly P units and g lly iH 2 t0 0 repeat ni polyvinyl chloride. These thiolanhydrides are desirable p ding t the formula Z,,],, h r n Z iS oxybecause they exhibit good long term stabilizing efficacy g f r f a miXtufe Of oxygen n lf r, H equals for both plasticized and rigid formulations, but they 15 and Ydenotes the degree of Polymerization Such as have never gained commercial importance because of methyltin Sulfide and Octyltin sulfide' the substantial discoloration of polymers which occurs Monohydrocarbyl tin Compounds Suitable for P during processing. The discoloration is unrelated to the tlclng the Present invention include Compounds Where stabilizing properties of the thiolanhydrides; however, R4 is a hydrocarbon radical Preferably yL- g it severely restricts the commercial use because of the one to 12 Carbon atomssome examples of Suitable serious detraction from the esthetic appeal of products. Compounds include the y butyl, y and I have discovered that organic thiolanhydrides conoctyl esters of both m0nohydrocarbyl Starmoic and taining Sma" amounts f monohydrocarbyltin ostannoic acids such as the isooctyl ester of butylstanpounds corresponding to the f l 40 noic acid and compounds of the formula R"Sn(SR 5 wherein is a hydrocarbyl group such as methyltin tris (Iauryl mercaptide), butyl tin tris containing one to 12 carbon atoms, Z and Z are indestearyl mercaptide) and QCtyl tris (stearyl p' pendently selected from oxygen and sulfur, R is hydro- Udelgen or an Organic radical bonded to by a carbon The monohydrocarbyl tin compounds can also have atom and n is a number from 0 to 1.5 varying in increa funcnonal group attached to by a Carbon atom and ments of one-half overcome the disadvantages of the are useful in Practicing the present invention Func prior an 7 tional groups of this type include Suitable thiolanhydrides for practicing the present invention include those where R and R are the same so 0 or different alkyl or aryl radicals. The alkyl radicals may be straight chain radicals producing anhydrides C alkyl; such as thiollauric or thiolstearic anhydride; branched acids and thiostannoic acids having one hydrocarbyl (CH- ,.COO alkyl;

(HUGO alkyl cylmereapto propionate) oxide and poly[butyl stan-z noxy cyclohexylidene bis (thiopropionate)].

The preferred monohydrocarbyl compounds for practicing the present invention are those which correspond to one of the following formulae:

wherein R is an alkyl having one to 12 carbon atoms, R is an alkyl having one to 20 carbon atoms, R is an alkyl having one to 12 carbon atoms, x is l or 2 and y is 2 to The monohydrocarbyl tin compounds are generally used in amounts varying from I to 25 weight per cent of the thiolanhydride in stabilizers of the present invention usually 2.5 to 15 weight per cent and preferably in amounts of 4 to 12 weight per cent. The synergistic stabilizers of the present invention are generally incorporated into a resin in amounts of (H to 10 weight per cent and preferably from 0.5 to weight per cent.

The synergistic action of the monohydrocarbyltin compounds of the present invention is demonstrated to be unexpected in view of the poor results obtained when diand trialkyl tin compounds are combined with The following examples are presented to demonstrate several embodiments of the present invention as well as several embodiments of the invention claimed in my above mentioned US. Pat. No. 3,630.993 and are not to be considered as limitations thereon.

EXAMPLE l Three formulations were prepared. Each formulation contained 100 parts GEON lO3P (a general purpose polyvinyl chloride resin suspension manufactured by B. F. Goodrich Company), 0.5 parts of mineral oil and a total of 2 parts of the stabilizer as indicated in Table 1. Each formulation was processed on a two roll mill at 320F. for 5 minutes and then divided into a number of 1 inch /2inch X 1/6 inch samples, the samples of each formulation were then placed in an air circulatory oven at 370 and a sample of each formulation was removed from the oven at minute intervals over an interval of one hour. Formulations l and 2 were tested for comparative purposes and do not represent embodiments of the present invention. Table 1 reports the composition of the stabilizers tested. Very slight discoloration represents the time at which visually detectable discoloration of the test sample was first noticed and moderate discoloration represents the time at which an orange or red discoloration was observed while suborganic thiolanhydride stabilizers.

Resins which may be stabilized by the synergistic composition of the present invention include both rigid and plasticized formulations of halogen containing polymers particularly polyvinyl chloride and polyvinylidene chloride, copolymers of halogen containing resins with ethylenically unsaturated compounds such as, copolymers of vinyl acetate and vinyl chloride and the like.

stantial discoloration or thermal decomposition was observed as very dark red, brown or black color in the sample.

TABLE 1 Stabilizer Time in minutes to: No. Composition in parts Very Moderate Suh- (p.) of formulation slight discolorstantial disation discolor coloration ation 60 l. 2.0 p. Thiollauric l() anhydride 2. 2.0 p. Methyl tin 0* 2U 4U sulfide 3. 1.9 p. Thioolauric 6s anhydride 4t) ().l p. Methyl tin sulfide Repeating this test using stearic thiolanydridu or benyoic thiolanhydride produce: suhslantiall the ame syiergistic imprmcment in com arison ith either of tin components alunc.

EXAMPLE 2 Formulations. each containing 100 parts of PVC 40 (a general purpose polyvinyl chloride resin manufactured by the Diamond-Shamrock Corp. 25 parts dioctylphthalate. 5 parts epoxidized soybean oil, 0.25 parts stearic acid and 2 parts of the respective stabilizers as indicated in Table 2, were milled. divided and exposed according to the procedure described in Example 1 The results of the tests are reported in Table 2.

EXAMPLE 3 Eight formulations were prepared as described in Example 2 for the respective stabilizers as indicated in Table 3 and the formulations were processed in the same manner described in Example 1 except oven exposure was extended 30 minutes. The following table reports the results of the test with formulations 1 and 5 not being embodiments of the present invention and included for comparative purposes only and with formulations 24 and 6-8 illustrating the invention claimed in my above-mentioned US. Pat. No. 3,630,993.

TABLE 3 Time in minutes to:

Moderate Substandistial colordiscoloration alion Stabilizer composition No. in parts (p.) Very slight discoloration slight yellowing developed during milling "very strong discoloration after 1!) minutes. decomposition at Xll minutes EXAMPLE 4 Three formulations were prepared containing parts of PVC 40 (a general purpose polyvinyl chloride resin manufactured by the Diamond-Shamrock Corp. 25 parts dioctylphthalate, 5 parts epoxidized soybean oil, 0.25 parts stearic acid and 2 parts of the respective TABLE 2 Stahiliver Composition in Time in minutes to: No. parts 1.) of formulation Very Moderate Substanslight discolorlial discoloration discolor ation alion *l 2.11 p. Thiollauric anhydride 10 21) 2 1.) p. 'l'hiollauric anhydride 0.1 p. mcthyllin tris (isooct \'l mercaptopro 3(1 40 51) PlUlllllU) *3 2.1 p. methyltin tris (isnoc! \l mercaplopro- 1U 2U 4U pionale) 4 1.9 p. lhiollauric anh \LIriLic 30 50 51) l p. hulyltin Iris (isoout nlcrcnptoacelalc) *5 1.1) p. hutyltin tris (isooctyl 1U 31) 4(1 mercaptoacetatc) o 1.9 p. 'lhiollauric anhydride (1.1 p. butyllin lris (isoiwtyl 2U 40 5(1 malcatcl *7 3.11 p. hutyltin iris (i.\'nu t 5 1(1 21) maleale '1 S 1.9 p. 'l'hiollauric anhydride 21) 3U 40 (1.1 p. octyltin trislearale I 2.0 p. oclyltin lrislcurale 1U 21) 31) 10 1.9 p. Thiollauric anhydride 3U 4U 51) 11.1 p. oclyltin Iris (la11r \1 mercaptitlcl *1 l 2.0 p. octyllin iris (la11r \l 15 25 -11) mcrcaplidc) These tests are nol HCLHHIIH]: t -\ell \\ing hug-an durinu 111111111:

stabilizers listed in Table 2 were milled. divided and exposed according to the procedure described in Example 1 except that the oven exposure was conducted for 90 minutes. The results of this test are reported in 32:25: 3 12: 22 g gs zgj filiggizg gi fi g g; 5 dride was varied between and 7.5 weight per cent 3 630 993 and formuilation l and 3 not g' b based on the thiollauric anhydridc. Each formulation the present invention and included for contained 2.0 parts thiollauric anhydride and the folparative purposes to demonstrate the synergistic effect lowmg table teports the reults of the above test for of the Stabilizers of the present invention each formulation. Formulation 1 does not represent the TABLE 4 present invention and formulations 24 represent the invention claimed in my above-mentioned US. Pat. No. 3,630,993. Stabilizer composition No. in parts (p.) Very Moderate Sub slight disstantial TABLE 6 discolordiscolorcoloration ation v n Amount of butyl Time in minutes Formulation stannoic acid to slight i 2.0 p. Thiollauric i0 90 in p P 100 discoloration anhydride 20 2 L9 pv Thiollauric l anhydride 2 0.05 20 0.1 p. buttylstannoic 5O 3 (H 30 aei 4 0.15 20 3 0.1 p. Butylstannoic l0 5() acid *Developed slight yellow color during milling "slight yellowing began during milling EXAMPLE 7 EXA 5 MPLE Six formulations were prepared according to the pro Six formulations more rigid than those of Examples cedure'of Example 6 except that monobutyltin tris [cywere P p y 100 Parts of Opalan 630 clohexylidene bis (thiopropionic acid) monobutyl es- Suspenslon of P y y Chlorlde manufactured by ter] was substituted for the butyl stannoic acid in Ex- Monsamo Cflrporanon), Parts dloctylphthalatcample 6 and the tests were extended to formulations Parts epoxlglzed f f' g r (F flf gi containing up to 20 per cent of the monobutyltin tris 251:"iiesiil licirii II,if; i'ieiffff (1. 26.183 CYCOhexylidene hmpmpim acid in ga inple 1 Table 5 ions 1: resu ts of s e ester]. The results of these tests are reported in Table Formulation l is not an embodiment of the present inz i ii i i I) accordlilg to the present i vention and is included for comparative purposes only. n me e or cOmPanSOT] P Formulations represent embodiments of the invem 4O Formulations 26 illustrate the invention claimed in my tion claimed in my above-mentioned US. Pat. No. above mennoned 3,630,993. TABLE 7 TABLE 5 Time to very St bili composition Ti in minutes 10 Formulation Amount of co-stabilizer slight or first No. in parts p.) slight discoloration in part per 100 discoloration l 2.0 p. Thiollauric anhydride l i) 2 1.9 p. Thiollauric anhydride 2 ()5 30 0.] p. monobutyltin tris 3 3Q [cyelohexylidene bis (thio- 5O 4 0. I5 30 propionic acid) monobutyl ester] 30 5 O 2 7O 3 1.9 p. Thiollauric anbydride 6 s 5 ().l p. polyhutyl stannoxy cyclohexylidene bis (thiopropionate)] 3U slight ellimmg developed during, milling 4 1.9 p. Thiollauric anhydride 5S 0.] p. butyl stannoic acid 30 5 1.9 p. Thiollauric anhydride ().l p. monobutyltin sulfide 20 EXAMPLE 8 6 3 Four formulations of 100 parts PVC 40, 25 parts di- (isooctylmercaptopropionate) 20 octyl phthalate, 5 parts epoxidized soybean oil, ().25 I r I I N parts of stearic acid, 1.9 parts thiollauric anhydride and 15C Urll l0 4 L' 'L! U KR Uflfl ml "1 L 0.1 part of the stabilizer as indicated in Table 8 were The formulation stabilized with thiollauric anhydride processed accordmg to the proccfiure Example alone developed early Color d i the milling Operw The results of the test are reported in Table 8. Formulation and had a distinct yellow color after 20 minutes of 1 Illustrates "Wemlon Claimed y aboveoven exposure while all formulations containing stabilizers of the present invention did not develop any dis coloration until 20 minutes of exposure to heat.

EXAMPLE 6 The procedure of Example 5 was followed to prepare four formulations except that the amount of butylstannoic acid used as the co-stabilizer with thiollauric anhymentioned patent and formulations 2-4 do not represent the present invention or the invention claimed in my above-mentioned US. Pat. No. 3,630,993.

TABLE 8 First Serious Formulation Stabilizer Composition Color Degradation I hutyl stannoic acid 40 90 2 dioctyl tin bis (isooctyl thioglycolate) 10 80 3 dioctyl tin maleale 10 80 4 bis trihutyl tin oxide 50 The test of Example 8 clearly demonstrates that only monohydrocarbyl tin compounds produce the synergistic results obtained by the stabilizers of the present invention.

EXAMPLE 9 Five formulations were prepared according to Example 1, except that 2.0 parts of the stabilizers or stabilizer combination set forth in Table 9 below were used.

The formulations were processed in the same manner described in Example 1. The following table gives the results wherein formulations 2 and 4 are embodiments of this invention and formulations l and 3 are not.

Eight preparations were made and tested as follows. In each preparation. a master batch consisted of 100 parts of PVC 40, a general purpose polyvinylchloride resin manufactured by Diamond-Shamrock Corporation. 25 parts dioctylphthalate, parts epoxidized soybean and 0.25 parts stearic acid. Equal portions of the master batch were blendedwith 2 parts per of, respectively, each one of the stabilizers or stabilizer combinations noted in Table 10 by milling for 5 minutes at 320F. The portions were sheeted off, cut into strips and tested in an air-circulating oven at 370F. At 10 minute intervals, a sample of each portion was removed and evaluated for early color and degradation by visual observation. The following Table reports the results of these tests. None of these preparations represent the present invention.

TABLE 10 No. Color Exposure in Minutes Thiollauric Dihydrocarbyltin Very Mod- Sub- Anhyslight erate stantial dride Amt. Amt. in pph. Name in 1 1.9 dibutyltin O. l 0 10 40 bis (isooctyl mercapto acetate 2 0.0 2.0 20 100 3 1.9 dibutyltin 0. l 0 10 30 bis (isooctyl maleate 4 0.0 2.0 20 100 5 1.9 dioctyltin 0. l 0 10 30 distearate 6 0.0 2.0 0 10 40 7 l .9 dioctyltin his (lauryl 0.1 0 10 30 mercaptide 8 0.0 2.0 [0 100 The results of the above tests show that, while the dihydrocarbyltin compounds used by themselves are good long term stabilizers, they provide little if any advantage when used in combination with thiollauric anhydride.

What is claimed is:

l. A stabilizing composition for vinyl halide resins selected from the group consisting of polyvinyl chloride, polyvinylidene chloride, copolymers of vinyl chloride and vinylidene chloride, copolymers of vinyl chloride with other ethylenically unsaturated monomers and mixtures thereof comprising a synergistic combination of l a thiolanhydride corresponding to the formula wherein R and R are hydrocarbyl radicals containg 6 to 20 carbon atoms and (2) 2.5 to 15 weight per cent based on said thiolanhydride of a monohydrocarbyltin compound corresponding to a formula selected from the group consisting of R"SnSSH, wherein R is an alkyl having one to 12 carbon atoms, R is an alkyl having one to 20 carbon atoms; R is an alkyl having one to 12 carbon atoms, x is 1 or 2 and y is at least 2.

2. The stabilizing composition of claim 1 wherein l is selected from the group consisting of thiollauric anhydride, thiolstearic anhydride and thiolbenzoic anhydride and (2) is selected from the group consisting of methyltin tris (isoocytl mercaptopropionate), butyltin tris (isooctyl mercaptoacetate), octyltin tristearate, butyltin tris (isooctyl maleate), octyltin tris (lauryl mercaptidc), bis (butyltin diisooctyl mercaptopropionate) oxide, methyltin sulfide and methylthiostannoic acid.

3. The stabilizing composition of claim 2 wherein (2) is 4 to 12 weight per cent methyltin tris (isooctyl mercaptopropionate 4. The stabilizing composition of claim 2 wherein (2) is 4 to 12 weight per cent butyltin tris (isooctyl mercaptoacetate 5. The stabilizing composition of claim 2 wherein (2) is 4 to 12 weight per cent methyltin sulfide.

it is. 2:1;

a lkyl 

1. A STABILIZING COMPOSITION FOR VINYL HALIDE RESINS SELECTED FROM THE GROUP CONSISTING OF POLYVINYL CHLORIDE, POLYVINYLIDENE CHLORIDE, COPOLYMERS OF VINYL CHLORIDE AND VINYLIDENE CHLORIDE, COPOLYMERS OF VINYL CHLORIDE WITH OTHER ETHYLENICALLY UNSATURATED MONOMERS AND MIXTURES THEREOF COMPRISING SYNERGISTIC COMBINATION OF (1) A THIOLANHYDRIDE CORRESPONDING TO THE FORMULA
 2. The stabilizing composition of claim 1 wherein (1) is selected from the group consisting of thiollauric anhydride, thiolstearic anhydride and thiolbenzoic anhydride and (2) is selected from the group consisting of methyltin tris (isoocytl mercaptopropionate), butyltin tris (isooctyl mercaptoacetate), octyltin tristearate, butyltin tris (isooctyl maleate), octyltin trIs (lauryl mercaptide), bis (butyltin diisooctyl mercaptopropionate) oxide, methyltin sulfide and methylthiostannoic acid.
 3. The stabilizing composition of claim 2 wherein (2) is 4 to 12 weight per cent methyltin tris (isooctyl mercaptopropionate).
 4. The stabilizing composition of claim 2 wherein (2) is 4 to 12 weight per cent butyltin tris (isooctyl mercaptoacetate).
 5. The stabilizing composition of claim 2 wherein (2) is 4 to 12 weight per cent methyltin sulfide.
 6. The stabilizing composition of claim 2 wherein (2) is 4 to 12 weight per cent methyl thiostannoic acid.
 7. The stabilizing composition of claim 2 wherein (2) is 4 to 12 weight per cent butyltin tris (isooctyl maleate).
 8. The stabilizing composition of claim 2 wherein (2) is 4 to 12 weight per cent octyltin tris (lauryl mercaptide).
 9. The stabilizing composition of claim 2 wherein (2) is 4 to 12 weight per cent octyltin tristearate.
 10. A polyvinyl chloride resin stabilized with 0.1 to 10% of the stabilizing composition of claim
 1. 